How a Virus Spreads, and How to Avoid It: A Former NASA Engineer Demonstrates with a Blacklight in a Classroom

The past few weeks have remind­ed us just why virus­es have been such a for­mi­da­ble ene­my of human­i­ty for so long. Though very few of the count­less virus­es in exis­tence affect us in any way, let alone a lethal one, we can’t see them with­out micro­scopes. And so when a dead­ly virus breaks out, we live our dai­ly lives with an invis­i­ble killer in our midst. Aggres­sive test­ing, as sev­er­al coro­n­avirus-afflict­ed coun­tries have proven, does much to low­er the rate of trans­mis­sion. But how, exact­ly, does trans­mis­sion hap­pen? In the video above, Youtu­ber Mark Rober, a for­mer NASA engi­neer and Apple prod­uct design­er, demon­strates the process vivid­ly by tak­ing a black­light into that most dis­eased of all envi­ron­ments: the ele­men­tary-school class­room.

You can’t see virus­es under a black­light, but you can see the spe­cial pow­der that Rober applies to the hands of the class’s teacher. At the begin­ning of the school day, the teacher shakes the hand of just three kids, touch­ing none of the oth­ers, and by lunchtime — a cou­ple of hours after Rober pow­ders the hands of one more stu­dent dur­ing morn­ing break — the black­light reveals the “germs” every­where.

This despite fair­ly dili­gent hand-wash­ing, albeit hand-wash­ing unac­com­pa­nied by the dis­in­fec­tion of sur­faces, cell­phones, and oth­er objects in and parts of the class­room. “Even if a virus is spread through air­borne trans­mis­sion,” Rober says, “those tiny droplets don’t stay in the air for long. Then they land on sur­faces, wait­ing to be touched by our hands.” This leads him to the dec­la­ra­tion that “the ulti­mate defense against catch­ing a virus is: just don’t touch your face.”

Rober calls your eyes, nose, and mouth “the sin­gle weak spot on the Death Star when it comes to virus­es. That’s the only way they can get in to infect you.” Hence, here in the time of COVID-19, the fre­quent urg­ings not just to wash our hands but to refrain from touch­ing our faces as well. Increas­ing­ly many of us have become hyper-aware of our own “germ hygiene,” as Rober calls it, but the oth­er half of the bat­tle against the pan­dem­ic must be insti­tu­tion­al: school clo­sures, for exam­ple, one of which was announced over the PA sys­tem dur­ing this very video’s shoot. “Because of this virus, we are going to be clos­ing school for three weeks,” says the prin­ci­pal, not with­out a note of excite­ment in his voice — but an excite­ment hard­ly com­pa­ra­ble to the sub­se­quent explo­sion of joy among the third-graders lis­ten­ing. Chal­leng­ing though this time may be, chil­dren like these remind us to take our fun wher­ev­er we find it.

Relat­ed Con­tent:

Inter­ac­tive Web Site Tracks the Glob­al Spread of the Coro­n­avirus: Cre­at­ed and Sup­port­ed by Johns Hop­kins

Free Cours­es on the Coro­n­avirus: What You Need to Know About the Emerg­ing Pan­dem­ic

Watch Bac­te­ria Become Resis­tant to Antibi­otics in a Mat­ter of Days: A Quick, Stop-Motion Film

The His­to­ry of the Plague: Every Major Epi­dem­ic in an Ani­mat­ed Map

Jared Dia­mond Iden­ti­fies the Real, Unex­pect­ed Risks in Our Every­day Life (in a Psy­che­del­ic Ani­mat­ed Video)

200 Free Kids’ Edu­ca­tion­al Resources: Video Lessons, Apps, Books, Web­sites & More

Based in Seoul, Col­in Mar­shall writes and broad­casts on cities, lan­guage, and cul­ture. His projects include the book The State­less City: a Walk through 21st-Cen­tu­ry Los Ange­les and the video series The City in Cin­e­ma. Fol­low him on Twit­ter at @colinmarshall or on Face­book.